Re: [PATCH] Notes on the warnings-as-errors change in GCC 14

[Florian Weimer <fweimer@redhat.com>]

* Sam James:

> It's fine if you leave this out, but consider mentioning the common
> pitfall of autoconf projects not including config.h consistently before
> all inclues. We could also mention AC_USE_SYSTEM_EXTENSIONS.

I added: 

“
Alternatively, projects using using Autoconf
could enable <code>AC_USE_SYSTEM_EXTENSIONS</code>.
”

<config.h> inclusion is a larger issue, I think, best addressed by
future diagnostics.

>> +<p>
>> +When building library code on GNU systems, it was possible to call
>> +undefined (not just undeclared) functions and still run other code in
>> +the library, particularly if ELF lazy binding was used.  Only
>> +executing the undefined function call would result in a lazy binding
>> +error and program crash.
>
> Maybe explicitly refer to the bfd linker's relaxed behaviour so it
> sounds less mysterious.

Like this?

“
<p>
When building library code on GNU systems,
<a href="https://sourceware.org/binutils/docs-2.42/ld/Options.html#index-_002d_002dallow_002dshlib_002dundefined">it was possible to call
  undefined (not just undeclared) functions</a>
and still run other code in the library, particularly if ELF lazy binding
was used.  Only executing the undefined function call would result in a
lazy binding error and program crash.
”

Thanks,
Florian